Shield bugs

Main species in New Zealand are Nezara viridula & Glaucias Amyoti

Also known as Stink Bugs, the adults are bright green, shield shaped and about 1.5cm long. Younger bugs are more rounded, and can be black and white or red. When attacked or disturbed they can release a fairly unpleasant smelling chemical. They lay their eggs in very distinct rows in clusters usually on the underside of the leaf.

They feed on a wide range of plants, including beans and tomatoes, generally by sucking sap from the plants. Though they will also feed directly from tomatoes and beans, causing discolouration and poor quality fruit. If only a few bugs are present the effect is often negligible. Severe infestations can cause poor quality fruit and reduce yields.

Prevention

Healthy, well fed plants are less likely to suffer from infestations.

Keep the garden clean and tidy as Shield Bug will lay eggs on some weed species.

Plant alyssum, borage, hyssop, and lavender to attract beneficial predator insects as many of them will feed on the shield bugs eggs. Calendula makes a great sacrificial plant.

Plant cleome, sunflowers, and mustard around the edge of your garden to lure the pest away from other crops, and periodically go through and remove eggs from leaves.

Treatment

Spraying BioNeem on infested plants can help control populations by disrupting feeding and mating. The trick here is to spray 2 times a week to control the infestation.

When using sprays and chemicals always read the label and follow instructions carefully. Spray in the evening to avoid harming beneficial insects.